Soft-biased shape anisotropic stabilized read head and method for manufacturing the same

Abstract

Soft-biased shape anisotropy-stabilized read head design and method for manufacturing the same. The present disclosure generally relates to a magnetic storage device, such as a tape drive, including a read head. The read head includes a plurality of read sensors disposed between a lower shield having a first width in a stripe height direction and an upper shield. The plurality of read sensors include an antiferromagnetic layer and a free layer including a first layer and a second layer. A plurality of soft-biased side shields are disposed adjacent to and outside the plurality of read sensors in a cross-track direction, each of the plurality of soft-biased side shields having a second width in the stripe height direction that is less than the first width. Each of the plurality of soft-biased side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to magnetic storage devices (eg, tape drives) including read heads and methods of forming the same. Background Art

[0002] Magnetic tape data storage is a system for storing digital information on magnetic tape using digital recording. Magnetic tape storage media is typically packaged in cartridges and cassettes. A tape drive writes or reads data from the cartridges or cassettes. A common cartridge-based format is LTO, which comes in various densities.

[0003] A tape drive operates by recording and reading back information from a magnetic tape using a tape head through a magnetic process. The tape head may have servo elements and data elements arranged in an array, sometimes referred to as a tape head array.

[0004] Hard bias elements adjacent to sensors in a tape drive can involve higher coercivity, which can hinder device performance. Soft bias elements involve lower coercivity but are unstable and can even move during tape drive operation. Soft bias elements can also cause signal shunting, hindering device performance.

[0005] Therefore, there is a need in the art for a tape drive having a soft biasing element that promotes low coercivity, stability of the soft biasing element, reduced signal shunting, and enhanced device performance. Summary of the Invention

[0006] The present disclosure generally relates to a magnetic storage device, such as a magnetic tape drive, including a read head. The read head includes a plurality of read sensors disposed between a lower shield having a first width in a stripe height direction and an upper shield. The plurality of read sensors include an antiferromagnetic layer and a free layer including a first layer and a second layer. A plurality of soft-bias side shields are disposed adjacent to and outside the plurality of read sensors in a cross-track direction, each of the plurality of soft-bias side shields having a second width in the stripe height direction that is less than the first width. Each of the plurality of soft-bias side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance.

[0007] In one embodiment, a read head includes: a lower shield having a first width in a stripe height direction; an upper shield; a lower conductive line disposed above the lower shield; one or more upper conductive lines disposed between the lower conductive line and the upper shield in a downward track direction; and a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multilayer structure including an antiferromagnetic (AFM) layer and a free layer. The read head further includes a plurality of soft bias side shields disposed between and outside the plurality of read sensors, each of the plurality of soft bias side shields having a second width in the stripe height direction that is less than the first width.

[0008] In another embodiment, a read head includes: a lower shield having a first width in a bar height direction and a first length in a cross-track direction; a lower conductive line disposed above the lower shield; an AFM layer disposed above the lower conductive line, the AFM layer having a second length in the cross-track direction substantially equal to the first length; and a plurality of read sensors disposed above the AFM layer at a medium-facing surface (MFS), each of the plurality of read sensors comprising a multilayer structure including: a portion of the AFM layer and a free layer including a first layer and a second layer. The read head further includes a plurality of soft bias side shields disposed between and outside the plurality of read sensors, each of the plurality of soft bias side shields having a second width in the bar height direction less than the first width; one or more upper conductive lines disposed above the plurality of read sensors; and an upper shield disposed above the one or more upper conductive lines.

[0009] In yet another embodiment, a read head includes: a lower shield having a first width in a stripe height direction; an upper shield; a lower conductive line disposed above the lower shield; one or more upper conductive lines disposed between the lower conductive line and the upper shield in a downward track direction; and a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multilayer structure including a buffer layer, an antiferromagnetic (AFM) layer, and a free layer including a first layer and a second layer. The read head further includes a plurality of soft bias side shields disposed between the plurality of read sensors and outside the plurality of read sensors, each of the plurality of soft bias side shields having a second width in the stripe height direction that is less than the first width. Each of the plurality of soft bias side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order that the manner in which the above-described features of the present disclosure may be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be made by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only typical embodiments of the present disclosure and are therefore not to be considered limiting of the scope of the present disclosure, as the present disclosure may admit to other equally effective embodiments.

[0011] Figure 1 is a schematic perspective exploded view of a storage device according to one embodiment.

[0012] Figure 2 According to an embodiment Figure 1 A schematic top view of a tape drive is shown in FIG.

[0013] Figure 3 According to an embodiment Figure 1 Schematic side profile view of the tape drive shown in .

[0014] Figures 4A to 4C Shown is a schematic view of a read head according to one embodiment.

[0015] FIG5A to FIG5B Shown is a schematic view of a read head according to one embodiment.

[0016] Figures 6 to 9 Various examples of read heads according to various embodiments are shown.

[0017] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized in other embodiments without specific recitation. DETAILED DESCRIPTION

[0018] Hereinafter, reference is made to embodiments of the present disclosure. However, it should be understood that the present disclosure is not limited to the specific described embodiments. In fact, any combination of the following features and elements (whether or not related to different embodiments) is encompassed to implement and practice the present disclosure. In addition, although the embodiments of the present disclosure may achieve advantages over other possible solutions and / or over the prior art, whether a particular advantage is achieved by a given embodiment does not limit the present disclosure. Therefore, the following aspects, features, embodiments and advantages are merely illustrative and are not considered to be elements or limitations of the appended claims unless expressly stated in the claims. Similarly, reference to "the present disclosure" should not be interpreted as a generalization of any inventive subject matter disclosed herein, and should not be considered to be elements or limitations of the appended claims unless expressly stated in the claims.

[0019] The present disclosure generally relates to a magnetic storage device, such as a magnetic tape drive, including a read head. The read head includes a plurality of read sensors disposed between a lower shield having a first width in a stripe height direction and an upper shield. The plurality of read sensors include an antiferromagnetic layer and a free layer including a first layer and a second layer. A plurality of soft-bias side shields are disposed adjacent to and outside the plurality of read sensors in a cross-track direction, each of the plurality of soft-bias side shields having a second width in the stripe height direction that is less than the first width. Each of the plurality of soft-bias side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance.

[0020] Figure 1 is a schematic perspective exploded view of a storage device 100 according to one embodiment. Storage device 100 is a magnetic media drive. Storage device 100 will be referred to hereinafter as tape drive 100. It should be noted that while the tape drive is shown with an embedded magnetic tape for illustrative purposes, embodiments of the present invention can be applied to various forms of tape drives, including drives in which tape media can be inserted, for example, into a media cartridge. One example is a tape drive and media compliant with the LTO standard, and the various drive illustrations shown will resemble such a drive when the media is fully inserted and engageable for data access.

[0021] Figure 2 According to an embodiment Figure 1 A schematic top view of a tape drive 100 is shown in FIG.

[0022] Figure 3 According to an embodiment Figure 1 A schematic side profile view of the tape drive 100 is shown in FIG.

[0023] For example, focusing on Figure 2 The tape drive 100 includes a housing including a casing 105, one or more tape reels 110, one or more rotors (e.g., a stepper motor 120 (also known as a stepper motor), a voice coil motor (VCM) 125, a head assembly 130 having one or more read heads and one or more write heads, and tape guides / rollers 135a, 135b. For example, focusing on Figure 3 , the tape drive 100 also includes a printed circuit board assembly 155 (PCBA). In one embodiment, which may be combined with other embodiments, most of the components are within the interior cavity of the housing 105, except for the PCBA 155 mounted on the outer surface of the housing 105. Figure 1 The same components are shown in perspective view in FIG.

[0024] In the illustrated embodiment, two tape reels 110 are placed in the interior cavity of the housing 105, with the center of each of the two tape reels 110 being at the same level in the cavity. Figure 1 and Figure 2 As shown in FIG, the head assembly 130 is located between and below the two tape reels 110. A tape reel motor located in the spindle of the tape reel 110 is operable to wind and unwind the tape media 115 in the tape reel 110. Each tape reel 110 may also be incorporated with a tape folder to help neatly wind the tape media 115 onto the corresponding tape reel 110. The tape media 115 may be manufactured via a sputtering process to provide improved areal density. The tape media 115 includes two surfaces, an oxide side and a substrate side. The oxide side is the surface that can be magnetically manipulated (written to or read from) by one or more read / write heads. The substrate side of the tape media 115 contributes to the strength and flexibility of the tape media 115.

[0025] The tape media 115 from the tape reel 110 is biased against guides / rollers 135a, 135b (collectively referred to as guides / rollers 135) and is movably transferred along the head assembly 130 by movement of the reel. The illustrated embodiment shows four guides / rollers 135a, 135b, with the two guides / rollers 135a being farthest from the head assembly 130 for changing the direction of the tape media 115, and the two guides / rollers 135b being closest to the head assembly 130 by pressing the tape media 115 against the head assembly 130.

[0026] In one embodiment, which may be combined with other embodiments, the guide / roller 135 utilizes the same structure, such as Figure 1 In one embodiment, which may be combined with other embodiments, the guides / rollers 135 may have more specific shapes and differ from each other based on function, such as Figure 2 As shown in FIG. A smaller or larger number of rollers can be used. For example, the two functional rollers can be cylindrical in shape, while the two functional guides can be flat-sided (e.g., rectangular prisms) or in the shape of a clamp with two prongs and a film that moves between the prongs of the clamp.

[0027] The voice coil motor 125 and the stepper motor 120 can variably position the tape head laterally relative to the width of the recording tape (e.g., the tape medium 115). The stepper motor 120 can provide coarse movement, while the voice coil motor 125 can provide finer actuation of the head of the head assembly 130. In one embodiment, which can be combined with other embodiments, servo data can be written to the tape medium 115 to facilitate more accurate positioning of the head along the tape medium 115.

[0028] The housing 105 includes one or more particle filters 141 and / or desiccants 142, such as Figure 1, to help maintain the environment within the housing 105. For example, if the housing 105 is not airtight, the particle filter 141 can be placed where airflow is expected. The particle filter 141 and / or desiccant 142 can be placed in one or more corners or any other convenient location away from moving internal components. For example, the moving tape reel 110 can generate internal airflow when the tape media 115 is wound / unwound, and the particle filter 141 can be placed within the airflow.

[0029] There are a wide variety of possible placements of the internal components of the tape drive 100 within the housing 105. Specifically, in some instances, when the head assembly 130 is within the housing 105, the tape media 115 may not be exposed to the exterior of the housing 105. Thus, the tape media 115 need not be routed along the edge of the housing 105 and may be freely routed within the housing 105 in a more compact and / or otherwise efficient manner. Similarly, the head and tape reel 110 may be placed in a variety of locations to achieve more efficient routing because there is no design requirement to provide external access to these components.

[0030] like Figure 3 As shown in FIG, the housing 105 includes a cover 150 and a base 145. A PCBA 155 is attached to the bottom of the exterior surface of the housing 105, opposite the cover 150. The base 145 includes three walls, and the cover 150 includes a fourth wall, forming four of the multiple walls of the housing 105 contained within the outer shell of the tape drive 100. Because the PCBA 155 is made of solid-state electronics, environmental issues are less of a concern, and therefore, it does not need to be placed inside the housing 105. This leaves room inside the housing 105 for other components that would benefit from a more protected environment, particularly the moving components and the tape media 115.

[0031] In one embodiment, which may be combined with other embodiments, the tape drive 100 is sealed. Sealed can mean that the tape drive 100 is hermetically sealed or simply sealed, not necessarily airtight. A sealed drive can benefit tape film winding stability, tape film reliability, and tape head reliability. A desiccant can be used to limit humidity inside the housing 105.

[0032] In one embodiment, which may be combined with other embodiments, the cover 150 is used to hermetically seal the tape drive 100. For example, the tape drive 100 may be hermetically sealed for environmental control by attaching (e.g., laser welding, adhering with an adhesive, etc.) the cover 150 to the base 145. The tape drive 100 may be filled with helium, nitrogen, hydrogen, or any other typical inert gas.

[0033] In one embodiment, which may be combined with other embodiments, other components may be added to the tape drive 100. For example, a preamplifier for the head of the head assembly 130 may be added to the tape drive 100. The preamplifier may be located on the PCBA 155, in the head assembly 130, or in another location. Generally speaking, placing the preamplifier closer to the head may have a greater impact on the signal-to-noise ratio (SNR) of the read and write signals. In one embodiment, which may be combined with other embodiments, some of the components may be omitted. For example, the particle filter 141 and / or the desiccant 142 may be omitted.

[0034] Figures 4A to 4C A schematic view of a read head 400 is shown according to one embodiment. Figure 4A is a schematic isometric view of a medium facing surface (MFS) of a read head 400 according to one embodiment. The read head 400 may be used as Figure 1 1. The magnetic tape drive 100 (magnetic storage device) shown in FIG. The read head 400 includes a lower shield (S1) 402, an upper shield (S2) 404, and a plurality of read sensors 420 disposed between the lower shield 402 and the upper shield 404. Although three read sensors 420 are shown in FIG. Figure 4A However, the read head 400 may include any number of read sensors 420, and the number of read sensors 420 is not intended to be limiting.

[0035] The lower conductor 406 is disposed between the lower shield 402 and the plurality of read sensors 420. Figure 4A As shown, lower conductors 406 are common to each read sensor 420. However, in some embodiments, each read sensor 420 may have a separate lower conductor 406 (not shown). Read head 400 includes a plurality of upper conductors 416 disposed above each of the plurality of read sensors 420 in a downward track direction (DT1). A first insulating layer 412 is disposed between upper shield 404 and the plurality of upper conductors 416. A second insulating layer 408 is disposed over lower conductors 406 and surrounds each of the read sensors 420 in the downward track direction. First insulating layer 412 and second insulating layer 408 may comprise the same material or different materials.

[0036] Each of the plurality of read sensors 420 includes a multilayer structure. The multilayer structure of each read sensor 420 includes a buffer layer 422 disposed on the lower conductive line 406, an antiferromagnetic (AFM) layer 424 disposed on the buffer layer 422, and a free layer 426 disposed on the AFM layer 424. Each read sensor 420 includes a cap layer 428 disposed on the free layer 426. The buffer layer 422 is disposed between the corresponding AFM layer 424 and the lower conductive line 406. The buffer layer 422 is substantially aligned with a portion of the second insulating layer 408 in the cross-track direction (CT1). The cap layer 428 is non-ferromagnetic. Each layer 422, 424, 426, and 428 in each read sensor 420 has a length in the cross-track direction that is less than the length of the lower shield 402 in the cross-track direction.

[0037] The read head 400 includes a plurality of soft bias side shields 410 disposed between a first insulating layer 412 and a second insulating layer 408, between and outside a plurality of read sensors 420. Each of the soft bias side shields 410 is magnetic, conductive, and has low coercivity. The soft bias side shields 410 facilitate a magnetic read field that biases the read sensors 420 during a magnetic read operation. The soft bias side shields 410 facilitate a magnetic field in a cross-track direction (CT1) during a magnetic read operation. A third insulating layer 440 is disposed between the first insulating layer 412 and the soft bias side shields 410, outside a plurality of upper conductive lines 416. The first insulating layer 412 and the third insulating layer 440 may comprise the same material or different materials.

[0038] The free layer 426 of each read sensor 420 includes a plurality of layers 430 through 433. The free layer 426 is ferromagnetic. It includes two layers, a first layer 430 and a second layer 432, separated by a spacer layer 431. Each of the two layers 430 and 432 is formed from one or more of cobalt (CO), iron (Fe), and / or boron (B). The spacer layer 431 is formed from magnesium oxide (MgO) and has a length in the downward track direction DT1 ranging from approximately 5 angstroms to approximately 200 angstroms, for example, approximately 20 angstroms. A barrier layer 433 of the free layer is disposed between the second layer 432 and the upper conductive line 416.

[0039] Figure 4B According to an embodiment Figure 4A Schematic isometric side cross-sectional view of the read head 400 shown in FIG. Figure 4BAs shown in FIG, the lower shield 402 and the lower conductive line 406 each have a first width W1 in the stripe height direction (SH1), from the MFS to the first surface 401 opposite the MFS. The second insulating layer 408, the soft-bias side shield 410, the read sensor 420, the third insulating layer 440, the first insulating layer 412, and the upper shield 404 each have a second width W2 in the stripe height direction, from the MFS to the second surface 403 opposite the MFS. The first width W1 is greater than the second width W2. In other words, the first surface 401 and the second surface 403 are not aligned.

[0040] During the formation of read head 400, lower shield 402, lower conductive line 406, and read sensor 420 are first deposited. A first photoresist (not shown) is deposited over a portion of read sensor 420 having a second length L2, and the remaining portion of read sensor 420 not covered by the first photoresist is milled away and removed. Second insulating layer 408 and soft bias side shields 410 are then deposited, and the first photoresist is removed. Upper conductive line 416 and third insulating layer 440 are then deposited and formed, followed by deposition of first insulating layer 412 and upper shield 404. A second photoresist (not shown) is deposited over a portion of upper shield 404 having a second width W2, and the remaining portions of second insulating layer 408, soft bias side shields 410, read sensor 420, third insulating layer 440, first insulating layer 412, and upper shield 404 are then milled away and removed. After grinding the portions of the second insulating layer 408, soft bias side shields 410, read sensors 420, third insulating layer 440, first insulating layer 412, and upper shield 404 not covered by the second photoresist, an insulating layer (not shown) is deposited to fill the removed portions, and the second photoresist is removed.

[0041] Figure 4C According to an embodiment Figure 4A Schematic cross-sectional view of the read head 400 along section 4C-4C is shown in FIG. Figure 4C The general cross-sectional view shown in Figures 5A to 9 5. The lower conductive line 406 between the lower shield 402 and the soft bias side shield 410 has a first thickness T1. The first insulating layer 412 and the upper conductive line 416 between the upper shield 404 and the soft bias side shield 410 collectively have a second thickness T2. The second thickness T2 is substantially equal to the first thickness T1, such that the difference between the second thickness T2 and the first thickness T1 is approximately 50 nm or less.

[0042] The second thickness T2 being substantially equal to the first thickness T1 facilitates stable read sensor 420, stabilizes the soft bias shield 410, and enhances magnetic read operation while minimizing signal shunting. In addition to the substantially equal first and second thicknesses T1 and T2, the soft bias shield 410 having a second width W2 in the stripe height direction that is less than the first width W1 further stabilizes the soft bias shield 410 through shape anisotropy. The shape of the soft bias shield 410 and the resulting shape anisotropy align the magnetized legs of the soft bias shield 410 in a desired direction, such as in the cross-track direction.

[0043] During a magnetic read operation, the tape medium 450 moves in the down-track direction DT1 past the read sensor 420. A portion 452 of the tape medium 450 aligned with the read sensor 420 along the stripe height direction SH1 experiences a first magnetic force F1. A portion 454 of the tape medium 450 aligned with the outer portion of the read sensor 420 along the stripe height direction SH1 experiences a second magnetic force F2 in the same direction as or opposite to the first magnetic force F1.

[0044] FIG5A to FIG5B A schematic view of a read head 500 is shown according to one embodiment. Figure 5A is a schematic isometric MFS view of a read head 500 according to one embodiment. The read head 500 may be used as Figure 1 1 and 2. A portion of a tape drive 100 (magnetic storage device) is shown in FIG. FIG5A to FIG5B The reading head 500 is similar to Figures 4A to 4C Therefore, for the same aspects in each of the read heads 400 and 500, Figures 4A to 4C and FIG5A to FIG5B Similar reference numerals are used in the accompanying drawings.

[0045] Although three read sensors 520 are shown FIG5A to FIG5B However, the read head 500 may include any number of read sensors 520, and the number of read sensors 520 is not intended to be limiting. FIG5A to FIG5B As shown in FIG, the lower conductor 406 is common to each read sensor 520. However, in some embodiments, each read sensor 520 may have a separate lower conductor 406 (not shown).

[0046] Each of the plurality of read sensors 520 includes a multilayer structure. The multilayer structure of each read sensor 520 includes a buffer layer 422 disposed on the lower conductive line 406, an AFM layer 424 disposed on the buffer layer 422, and a free layer 526 disposed on the AFM layer 424. Each read sensor 420 includes a cap layer 428 disposed on the free layer 526. The buffer layer 422 is disposed between the corresponding AFM layer 424 and the lower conductive line 406. The cap layer 428 is non-ferromagnetic. The buffer layer 422 and the AFM layer 424 are common to each of the sensors 520. In other words, each sensor 520 includes a portion of the buffer layer 422 and a portion of the AFM layer 424, such that the common portion of the buffer layer 422 and the common portion of the AFM layer 424 span the plurality of read sensors 520.

[0047] The free layer 526 of each read sensor 520 includes a plurality of layers 430 through 433. The free layer 526 is ferromagnetic. The free layer 526 includes two layers, a first layer 430 and a second layer 432, separated by a spacer layer 431. The barrier layer 433 of the free layer 526 is disposed between the second layer 432 and the upper conductive line 416. The read head 500 differs from the read head 400 in that each free layer 526 of each read sensor 520 shares a common first layer 430, while each read sensor 520 has its own individual spacer layer 431, second layer 432, and barrier layer 433. In other words, each sensor 520 includes a portion of the first layer 430, such that the common portion of the first layer 430 spans across multiple read sensors 520. In addition, the buffer layer 422 and the AFM layer 424 have the same length in the cross-track direction and the same width (i.e., W1) as the lower shield 402 in the stripe height direction. The second insulating layer 408 is disposed on the first layer 430 of the free layer 526 and surrounds each of the read sensors 520 in the down-track direction.

[0048] The read head 500 includes a plurality of soft bias side shields 410 disposed between the first insulating layer 412 and the second insulating layer 408, between and outside the spacer layer 431, the second layer 432, the barrier layer 433, and the cap layer 428 of each of the read sensors 420. Each of the soft bias side shields 410 is magnetic, conductive, and has low coercivity. The soft bias side shields 410 facilitate biasing the magnetic read field of the read sensor 520 during a magnetic read operation. The soft bias side shields 410 facilitate a magnetic field in the cross-track direction during a magnetic read operation. A third insulating layer 440 is disposed between the first insulating layer 412 and the soft bias side shields 410, outside the plurality of upper conductive lines 416. The third insulating layer 440 has a second width W2 in the stripe height direction. The first insulating layer 412 and the third insulating layer 440 may include the same material or different materials.

[0049] As discussed above and as Figure 4C As shown, the lower conductive line 406 between the lower shield 402 and the soft bias side shield 410 has a first thickness T1. The first insulating layer 412 and the upper conductive line 416 between the upper shield 404 and the soft bias side shield 410 collectively have a second thickness T2. The second thickness T2 is substantially equal to the first thickness T1, such that the difference between the second thickness T2 and the first thickness T1 is approximately 50 nm or less. The second thickness T2 being substantially equal to the first thickness T1 facilitates stable read sensor 520, stabilizes the soft bias shield 410, and enhances magnetic read operation while minimizing signal shunting. In addition to the first and second thicknesses T1 and T2 being substantially equal, the soft bias shield 410 having a second width W2 in the stripe height direction that is less than the first width W1 further stabilizes the soft bias shield 410 through shape anisotropy. The shape and resulting shape anisotropy of the soft bias shield 410 causes the magnetized legs of the soft bias shield 410 to be in a desired direction, such as in a cross-track direction.

[0050] The lower shield 402, the lower conductive line 406, the buffer layer 422, the AFM layer 424, the first layer 430 of the free layer 526, the first insulating layer 412, the second insulating layer 408, the third insulating layer 440, and the upper shield 404 each have a first length L1 in the cross-track direction. The spacer layer 431 of the free layer 526, the second layer 432 of the free layer 526, the barrier layer 433 of the free layer 526, the cap layer 428, and the upper conductive line 416 each have a second length L2 in the cross-track direction. The second length L2 is less than the first length L1.

[0051] Figure 5B According to an embodiment Figure 5ASchematic isometric side cross-sectional view of the read head 500 shown in FIG. Figure 5B As shown in FIG, the lower shield 402, the lower conductive line 406, the buffer layer 422, the AFM layer 424, and the first layer 430 of the free layer 526 each have a first width W1 in the stripe height direction, from the MFS to the first surface 401 opposite the MFS. The second insulating layer 408, the soft bias side shield 410, the spacer layer 431 of the free layer 526, the second layer 432 of the free layer 526, the barrier layer 433 of the free layer 526, the cap layer 428, the third insulating layer 440, the first insulating layer 412, the upper conductive line 416, and the upper shield 404 each have a second width W2 in the stripe height direction, from the MFS to the second surface 403 opposite the MFS. The first width W1 is greater than the second width W2. In other words, the first surface 401 and the second surface 403 are not aligned.

[0052] During formation of read head 500, lower shield 402, lower conductive line 406, and read sensor 520 are first deposited. A first photoresist (not shown) is deposited over the portion of read sensor 520 having second length L2, and then the remaining or exposed portions of cap layer 428, barrier layer 433 of free layer 526, second layer 432 of free layer 526, and spacer layer 431 of free layer 526 are ground away and removed. Second insulating layer 408 and soft-bias side shield 410 are then deposited and the first photoresist removed. Upper conductive line 416 and third insulating layer 440 are deposited and formed, followed by deposition of first insulating layer 412 and upper shield 404.

[0053] A second photoresist (not shown) is deposited over a portion of the upper shield 404 having a third width W2, and the second insulating layer 408, the soft bias side shield 410, the spacer layer 431 of the free layer 526, the second layer 432 of the free layer 526, the barrier layer 433 of the free layer 526, the top cap layer 428, the first insulating layer 412, the upper conductive line 416, the third insulating layer 440, and the remaining or exposed portion of the upper shield 404 are ground away and removed. After grinding the second insulating layer 408, the soft bias side shield 410, the spacer layer 431 of the free layer 526, the second layer 432 of the free layer 526, the barrier layer 433 of the free layer 526, the top cap layer 428, the first insulating layer 412, the upper conductive line 416, the third insulating layer 440 and the portions of the upper shield 404 not covered by the second photoresist, an insulating layer (not shown) is deposited to fill the removed portions, and the second photoresist is removed.

[0054] Figure 6 is a schematic isometric MFS view of a read head 600 according to another embodiment. The read head 600 may be used as Figure 11 and 2. A portion of a tape drive 100 (magnetic storage device) is shown in FIG. Figure 6 The read head 600 is similar to Figures 4A to 4C The reading head 400 is similar to FIG5A to FIG5B Therefore, for the same aspects in each of the read heads 400, 500, and 600, Figures 4A to 4C 、 FIG5A to FIG5B and Figure 6 Similar reference numerals are used in the accompanying drawings.

[0055] Although two read sensors 620 are shown Figure 6 However, the read head 600 may include any number of read sensors 620, and the number of read sensors 620 is not intended to be limiting. Figure 6 As shown in FIG, the lower conductor 406 is common to each read sensor 620. However, in some embodiments, each read sensor 620 may have a separate lower conductor 406 (not shown).

[0056] Each of the plurality of read sensors 620 includes a multilayer structure. The multilayer structure of each read sensor 620 includes a buffer layer 422 disposed on the lower conductive line 406, an AFM layer 424 disposed on the buffer layer 422, and a free layer 626 disposed on the AFM layer 424. Each read sensor 420 includes a cap layer 428 disposed on the free layer 626. The buffer layer 422 is disposed between the corresponding AFM layer 424 and the lower conductive line 406. The cap layer 428 is non-ferromagnetic. The buffer layer 422 and the AFM layer 424 are common to each of the sensors 620. In other words, each sensor 620 includes a portion of the buffer layer 422 and a portion of the AFM layer 424, such that the common portion of the buffer layer 422 and the common portion of the AFM layer 424 span across the plurality of read sensors 620.

[0057] The free layer 626 of each read sensor 620 includes a plurality of layers 430 through 433. The free layer 626 is ferromagnetic. The free layer 626 includes two layers, a first layer 430 and a second layer 432, separated by a spacer layer 431. The barrier layer 433 of the free layer 626 is disposed between the second layer 432 and the upper conductive line 416. Read head 600 differs from read head 400 in that each free layer 626 of each read sensor 620 shares a common first layer 430, while each read sensor 620 has its own individual spacer layer 431, second layer 432, and barrier layer 433. In other words, each sensor 620 includes a portion of the first layer 430, such that the common portion of the first layer 430 spans across multiple read sensors 620. Additionally, the buffer layer 422 and the AFM layer 424 have the same length in the cross-track direction and the same width in the stripe height direction as the lower shield 402 (i.e., W1), and the buffer layer 422 and the AFM 424 are common to each sensor 620. The second insulating layer 408 is disposed on the first layer 430 of the free layer 626 and surrounds each of the read sensors 620 in the down-track direction.

[0058] The read head 600 includes a plurality of soft bias side shields 410 disposed between the first insulating layer 412 and the second insulating layer 408, and between and outside the spacer layer 431, the second layer 432, the barrier layer 433, and the cap layer 428 of each of the read sensors 620. Each of the soft bias side shields 410 is magnetic, conductive, and has low coercivity. The soft bias side shields 410 bias the magnetic read field of the read sensor 620 during a magnetic read operation. The soft bias side shields 410 promote a magnetic field in the cross-track direction during a magnetic read operation.

[0059] Read head 600 differs from read head 500 in that a third insulating layer 640 is positioned between first insulating layer 412 and the plurality of soft-bias side shields 410 adjacent to upper conductive line 416. Third insulating layer 640 may comprise the same material as first insulating layer 412 or a different material. Furthermore, each of the plurality of soft-bias side shields 410, each of the sensors 620, and second insulating layer 408 have a third width W3 extending from the MFS toward surface 401 opposite the MFS in the stripe height direction. A fourth insulating layer 642 is positioned behind each of the plurality of soft-bias side shields 410, each of the sensors 620, and second insulating layer 408 between third insulating layer 640 and first layer 430. Fourth insulating layer 642 may comprise the same material as first insulating layer 412 or a different material.

[0060] Fourth insulating layer 642 has a fourth width W4 in the stripe height direction, extending from the plurality of soft-bias side shields 410, each sensor 620, and second insulating layer 408 to surface 401 opposite the MFS. Lower shield 402, lower conductive line 406, buffer layer 422, AFM layer 424, first layer 430, third insulating layer 640, first insulating layer 412, and upper shield 404 each have a first width W1 in the stripe height direction that is greater than third width W3. Third width W3 and fourth width W4 are collectively equal to first width W1.

[0061] As discussed above and as Figure 4C As shown, the lower conductive line 406 between the lower shield 402 and the soft bias side shield 410 has a first thickness T1. The first insulating layer 412 and the upper conductive line 416 between the upper shield 404 and the soft bias side shield 410 collectively have a second thickness T2. The second thickness T2 is substantially equal to the first thickness T1, such that the difference between the second thickness T2 and the first thickness T1 is approximately 50 nm or less. The second thickness T2 being substantially equal to the first thickness T1 facilitates stable read sensor 420, stabilizes the soft bias shield 410, and enhances magnetic read operation while minimizing signal shunting. In addition to the substantially equal first and second thicknesses T1 and T2, the soft bias shield 410 having a third width W3 in the stripe height direction that is less than the first width W1 further stabilizes the soft bias shield 410 through shape anisotropy. The shape and resulting shape anisotropy of the soft bias shield 410 causes the magnetized legs of the soft bias shield 410 to be in a desired direction, such as in a cross-track direction.

[0062] During formation of the read head 600, the lower shield 402, lower conductive line 406, and read sensor 620 are first deposited. A first photoresist (not shown) is deposited over the portion of the read sensor 620 having the second length L2, and then the remaining or exposed portions of the cap layer 428, the barrier layer 433 of the free layer 626, the second layer 432 of the free layer 626, and the spacer layer 431 of the free layer 626 are ground away and removed. The second insulating layer 408 and the soft bias side shield 410 are then deposited, and the first photoresist is removed. A second photoresist (not shown) is deposited over portions of the second insulating layer 408, the soft bias side shields 410, the spacer layer 431 of the free layer 626, the second layer 432 of the free layer 626, and the barrier layer 433 of the free layer 626 having a third width W3, and is subsequently ground away and the remaining portions of the second insulating layer 408, the soft bias side shields 410, the spacer layer 431 of the free layer 626, the second layer 432 of the free layer 626, and the barrier layer 433 of the free layer 626 are removed.

[0063] After grinding the second insulating layer 408, the soft bias side shield 410, the spacer layer 431 of the free layer 626, the second layer 432 of the free layer 626, and the portion of the barrier layer 433 of the free layer 626 not covered by the second photoresist, a fourth insulating layer 642 is deposited and the second photoresist is removed. A third insulating layer 640, the first insulating layer 412, the upper conductive line 416, and the upper shield 404 are subsequently deposited and formed over the fourth insulating layer 642 and the sensor 620.

[0064] Figure 7 is a schematic isometric MFS view of a read head 700 according to one embodiment. The read head 700 may be used as Figure 1 1 and 2. A portion of a tape drive 100 (magnetic storage device) is shown in FIG. Figure 7 The read head 700 is similar to Figures 4A to 4C Read head 400, FIG5A to FIG5B Read head 500 and Figure 6 Therefore, for the same aspects in each of the read heads 400, 500, 600, and 700, Figures 4A to 4C 、 FIG5A to FIG5B 、 Figure 6 and Figure 7 Similar reference numerals are used in the accompanying drawings.

[0065] Although two read sensors 720 are shown Figure 7 However, the read head 700 may include any number of read sensors 720, and the number of read sensors 720 is not intended to be limiting. Figure 7 As shown in FIG, the lower conductor 406 is common to each read sensor 720. However, in some embodiments, each read sensor 720 may have a separate lower conductor 406 (not shown).

[0066] Each of the plurality of read sensors 720 includes a multilayer structure. The multilayer structure of each read sensor 720 includes a buffer layer 422 disposed on the lower conductive line 406, an AFM layer 424 disposed on the buffer layer 422, and a free layer 726 disposed on the AFM layer 424. Each read sensor 420 includes a cap layer 428 disposed on the free layer 726. The buffer layer 422 is disposed between the corresponding AFM layer 424 and the lower conductive line 406. The cap layer 428 is non-ferromagnetic. The buffer layer 422 and the AFM layer 424 are common to each of the sensors 720. In other words, each sensor 720 includes a portion of the buffer layer 422 and a portion of the AFM layer 424, such that the common portion of the buffer layer 422 and the common portion of the AFM layer 424 span the plurality of read sensors 720.

[0067] The free layer 726 of each read sensor 720 includes multiple layers 430 through 433. The free layer 726 is ferromagnetic. It includes two layers, a first layer 430 and a second layer 432, separated by a spacer layer 431. The barrier layer 433 of the free layer 726 is disposed between the second layer 432 and the upper conductive line 416. Read head 700 differs from read head 400 in that each free layer 726 of each read sensor 720 shares a common first layer 430, while each read sensor 720 has its own individual spacer layer 431, second layer 432, and barrier layer 433. In other words, each sensor 720 includes a portion of the first layer 430, such that the common portion of the first layer 430 spans across multiple read sensors 720. Furthermore, the buffer layer 422 and the AFM layer 424 have the same length as the lower shield 402 in the cross-track direction, and the buffer layer 422 and the AFM layer 424 are common to each sensor 720. The second insulating layer 408 is disposed on the first layer 430 of the free layer 726 and surrounds each of the read sensors 720 in the down-track direction.

[0068] The read head 700 includes a plurality of soft bias side shields 410 disposed between the first insulating layer 412 and the second insulating layer 408, and between and outside the spacer layer 431, the second layer 432, the barrier layer 433, and the cap layer 428 of each of the read sensors 720. Each of the soft bias side shields 410 is magnetic, conductive, and has low coercivity. The soft bias side shields 410 facilitate biasing the magnetic read field of the read sensor 720 during a magnetic read operation. The soft bias side shields 410 facilitate biasing the magnetic field in the cross-track direction during a magnetic read operation.

[0069] Read head 700 differs from read head 600 in that each of the plurality of soft-bias side shields 410, each of the sensors 720, the second insulating layer 408, the first layer 430, the AFM layer 424, and the buffer layer 422 have a third width W3 in the stripe height direction, extending from the MFS toward the surface 401 opposite the MFS. A fifth insulating layer 744 is disposed between the third insulating layer 640 and the lower conductive line 406, behind each of the plurality of soft-bias side shields 410, each of the sensors 620, the second insulating layer 408, the first layer 430, the AFM layer 424, and the buffer layer 422. The fifth insulating layer 744 may include the same material as the first insulating layer 412 or a different material. The fifth insulating layer 744 has a fourth width W4 in the stripe height direction, extending from the plurality of soft-bias side shields 410, each of the sensors 620, the second insulating layer 408, the first layer 430, the AFM layer 424, and the buffer layer 422 to the surface 401 opposite the MFS. The lower shield 402, the lower conductive line 406, the third insulating layer 640, the first insulating layer 412, and the upper shield 404 each have a first width W1 in the stripe height direction that is greater than the third width W3. The third width W3 and the fourth width W4 are collectively equal to the first width W1.

[0070] As discussed above and as Figure 4C As shown, the lower conductive line 406 between the lower shield 402 and the soft bias side shield 410 has a first thickness T1. The first insulating layer 412 and the upper conductive line 416 between the upper shield 404 and the soft bias side shield 410 collectively have a second thickness T2. The second thickness T2 is substantially equal to the first thickness T1, such that the difference between the second thickness T2 and the first thickness T1 is approximately 50 nm or less. The second thickness T2 being substantially equal to the first thickness T1 facilitates stable read sensor 420, stabilizes the soft bias shield 410, and enhances magnetic read operation while minimizing signal shunting. In addition to the substantially equal first and second thicknesses T1 and T2, the soft bias shield 410 having a third width W3 in the stripe height direction that is less than the first width W1 further stabilizes the soft bias shield 410 through shape anisotropy. The shape and resulting shape anisotropy of the soft bias shield 410 causes the magnetized legs of the soft bias shield 410 to be in a desired direction, such as in a cross-track direction.

[0071] During formation of the read head 700, the lower shield 402, lower conductive line 406, and read sensor 720 are first deposited. A first photoresist (not shown) is deposited over the portion of the read sensor 720 having the second length L2, and then the remaining or exposed portions of the cap layer 428, the barrier layer 433 of the free layer 726, the second layer 432 of the free layer 726, and the spacer layer 431 of the free layer 726 are ground away and removed. The second insulating layer 408 and the soft bias side shield 410 are then deposited, and the first photoresist is removed. A second photoresist (not shown) is deposited over the buffer layer 422, the AFM layer 424 and the first layer 430 of the free layer 726, the second insulating layer 408, the soft bias side shield 410, the spacer layer 431 of the free layer 726, the second layer 432 of the free layer 726 and a portion of the barrier layer 433 of the free layer 726 having a third width W3, and is subsequently ground away and removed.

[0072] After grinding the buffer layer 422, the AFM layer 424, and the first layer 430 of the free layer 726, the second insulating layer 408, the soft bias side shield 410, the spacer layer 431 of the free layer 726, the second layer 432 of the free layer 726, and the barrier layer 433 of the free layer 726 that are not covered by the second photoresist, the fifth insulating layer 744 is deposited and the second photoresist is removed. The third insulating layer 640, the first insulating layer 412, the upper conductive line 416, and the upper shield 404 are then deposited and formed over the fourth insulating layer 642 and the sensor 720.

[0073] Figure 8 is a schematic isometric MFS view of a read head 800 according to yet another embodiment. The read head 800 may be used as Figure 1 1 and 2. A portion of a tape drive 100 (magnetic storage device) is shown in FIG. Figure 8 The reading head 800 is similar to Figures 4A to 4C Read head 400, FIG5A to FIG5B Reading head 500, Figure 6 Read head 600 and Figure 7 Therefore, for the same aspects in each of the read heads 400, 500, 600, 700, and 800, Figures 4A to 4C 、 FIG5A to FIG5B 、 Figure 6 、 Figure 7 and Figure 8 Similar reference numerals are used in the accompanying drawings.

[0074] Although two read sensors 820 are shown Figure 8 However, the read head 800 may include any number of read sensors 820, and the number of read sensors 820 is not intended to be limiting. Figure 8 As shown in FIG, the lower conductor 406 is common to each read sensor 820. However, in some embodiments, each read sensor 820 may have a separate lower conductor 406 (not shown).

[0075] Each of the plurality of read sensors 820 includes a multilayer structure. The multilayer structure of each read sensor 820 includes a buffer layer 422 disposed on the lower conductive line 406, an AFM layer 424 disposed on the buffer layer 422, and a free layer 826 disposed on the AFM layer 424. Each read sensor 420 includes a cap layer 428 disposed on the free layer 826. The buffer layer 422 is disposed between the corresponding AFM layer 424 and the lower conductive line 406. The cap layer 428 is non-ferromagnetic.

[0076] The read head 800 includes a plurality of soft bias side shields 410 disposed between the first insulating layer 412 and the second insulating layer 408, between the plurality of read sensors 820, and outside the plurality of read sensors 820 (i.e., outside the first layer 430, the spacer layer 431, the second layer 432, the barrier layer 433, and the cap layer 428). Each of the soft bias side shields 410 is magnetic, conductive, and has low coercivity. The soft bias side shields 410 facilitate a magnetic read field that biases the read sensors 820 during a magnetic read operation. The soft bias side shields 410 facilitate a magnetic field in the cross-track direction during a magnetic read operation.

[0077] The free layer 826 of each read sensor 820 includes a plurality of layers 430 through 433. The free layer 826 is ferromagnetic. The free layer 826 includes two layers, a first layer 430 and a second layer 432, separated by a spacer layer 431. The barrier layer 433 of the free layer 826 is disposed between the second layer 432 and the upper conductive line 416. Read head 800 is similar to read head 400 in that each read sensor 820 has its own individual buffer layer 422, AFM layer 424, first layer 430, spacer layer 431, second layer 432, and barrier layer 433. A second insulating layer 408 is disposed on the lower conductive line 406 and surrounds the read sensor 820.

[0078] Read head 800 differs from read head 400 but is similar to read heads 600 and 700 in that each of the plurality of soft-bias side shields 410, each of the sensors 820, and the second insulating layer 408 has a third width W3 in the stripe height direction, extending from the MFS toward the surface 401 opposite the MFS. A fifth insulating layer 744 is positioned behind each of the plurality of soft-bias side shields 410, each of the sensors 820, and the second insulating layer 408, between the third insulating layer 640 and the lower conductive line 306. The fifth insulating layer 744 has a fourth width W4 in the stripe height direction, extending from the plurality of soft-bias side shields 410, each of the sensors 820, and the second insulating layer 408 to the surface 401 opposite the MFS. Lower shield 402, lower conductive line 406, third insulating layer 640, first insulating layer 412, and upper shield 404 each have a first width W1 in the stripe height direction that is greater than the third width W3. The third width W3 and the fourth width W4 are collectively equal to the first width W1 .

[0079] As discussed above and as Figure 4C As shown, the lower conductive line 406 between the lower shield 402 and the soft bias side shield 410 has a first thickness T1. The first insulating layer 412 and the upper conductive line 416 between the upper shield 404 and the soft bias side shield 410 collectively have a second thickness T2. The second thickness T2 is substantially equal to the first thickness T1, such that the difference between the second thickness T2 and the first thickness T1 is approximately 50 nm or less. The second thickness T2 being substantially equal to the first thickness T1 facilitates stable read sensor 420, stabilizes the soft bias shield 410, and enhances magnetic read operation while minimizing signal shunting. In addition to the substantially equal first and second thicknesses T1 and T2, the soft bias shield 410 having a third width W3 in the stripe height direction that is less than the first width W1 further stabilizes the soft bias shield 410 through shape anisotropy. The shape and resulting shape anisotropy of the soft bias shield 410 causes the magnetized legs of the soft bias shield 410 to be in a desired direction, such as in a cross-track direction.

[0080] During formation of read head 800, lower shield 402, lower conductive line 406, and read sensor 820 are first deposited. Buffer layer 422, AFM layer 424, and soft bias side shield 410 are then deposited. A first photoresist (not shown) is deposited over the portion of read sensor 820 having a second length L2, and the remaining or exposed portion of read sensor 820 is milled away and removed. Second insulating layer 408 and soft bias side shield 410 are then deposited, and the first photoresist is removed. A second photoresist (not shown) is deposited over buffer layer 422, AFM layer 424, read sensor 820, and the portion of soft bias side shield 410 having a third width W3, and the remaining portions of second insulating layer 408, buffer layer 422, AFM layer 424, read sensor 820, and soft bias side shield 410 are then milled away and removed. After grinding the portions of second insulating layer 408, buffer layer 422, AFM layer 424, read sensor 820, and soft bias side shield 410 not covered by the second photoresist, fifth insulating layer 744 is deposited and the second photoresist is removed. Third insulating layer 640, first insulating layer 412, upper conductive line 416, and upper shield 404 are then deposited and formed over fourth insulating layer 642 and sensor 820.

[0081] Figure 9 is a schematic isometric MFS view of a read head 900 according to another embodiment. The read head 900 may be used as Figure 1 1 and 2. A portion of a tape drive 100 (magnetic storage device) is shown in FIG. Figure 9 The reading head 900 is similar to Figures 4A to 4C Read head 400, FIG5A to FIG5B Reading head 500, Figure 6 Read head 600, Figure 7 Read head 700 and Figure 8 Therefore, for the same aspects in each of the read heads 400, 500, 600, 700, 800, and 900, Figures 4A to 4C 、 FIG5A to FIG5B 、 Figure 6 、 Figure 7 、 Figure 8 and Figure 9 Similar reference numerals are used in the accompanying drawings. Figures 4A to 9 Each read head 400, read head 500, read head 600, read head 700, read head 800, read head 900 can be used in combination with each other.

[0082] Although two read sensors 920 are shown Figure 9 However, the read head 900 may include any number of read sensors 920, and the number of read sensors 920 is not intended to be limiting. Figure 9As shown in FIG, the lower conductor 406 is common to each read sensor 920. However, in some embodiments, each read sensor 920 may have a separate lower conductor 406 (not shown).

[0083] Each of the plurality of read sensors 920 includes a multilayer structure. The multilayer structure of each read sensor 920 includes a buffer layer 422 disposed on the lower conductive line 406, an AFM layer 424 disposed on the buffer layer 422, and a free layer 926 disposed on the AFM layer 424. Each read sensor 420 includes a cap layer 428 disposed on the free layer 926. The buffer layer 422 is disposed between the corresponding AFM layer 424 and the lower conductive line 406. The cap layer 428 is non-ferromagnetic.

[0084] The free layer 926 of each read sensor 920 includes a plurality of layers 430 through 433. The free layer 926 is ferromagnetic. The free layer 926 includes two layers, a first layer 430 and a second layer 432, separated by a spacer layer 431. The barrier layer 433 of the free layer 926 is disposed between the second layer 432 and the upper conductive line 416. Read head 900 is similar to read heads 400 and 800 in that each read sensor 920 has its own individual buffer layer 422, AFM layer 424, first layer 430, spacer layer 431, second layer 432, and barrier layer 433. A second insulating layer 408 is disposed on the lower conductive line 406 and surrounds the read sensor 920.

[0085] The read head 900 includes a plurality of soft bias side shields 410 disposed between the third insulating layer 640 and the second buffer layer 948, between the spacer layer 431, the second layer 432, the barrier layer 433, and the cap layer 428 of each of the read sensors 920, and outside the spacer layer 431, the second layer 432, the barrier layer 433, and the cap layer 428 of each of the read sensors 920. The second buffer layer 948 is disposed between the first layer 430 and the AFM layer 424 adjacent to the second insulating layer 408, and outside the first layer 430 and the AFM layer 424. The second buffer layer 948 is non-magnetic and conductive. Each of the soft bias side shields 410 is magnetic, conductive, and has low coercivity. The soft bias side shields 410 facilitate the magnetic read field that biases the read sensor 920 during a magnetic read operation. The soft bias side shields 410 facilitate the magnetic field in the cross-track direction during a magnetic read operation.

[0086] Read head 900 differs from read head 400 but is similar to read head 800 in that each of the plurality of soft-bias side shields 410, each of the sensors 920, and the second insulating layer 408 have a third width W3 extending from the MFS toward the surface 401 opposite the MFS. A sixth insulating layer 946 is disposed behind each of the plurality of soft-bias side shields 410 and the spacer layer 431, the second layer 432 of each sensor 920, the barrier layer 433, and the cap layer 428. The sixth insulating layer 946 is further disposed between the second buffer layer 948 and the third insulating layer 640. The sixth insulating layer 946 may include the same material as the first insulating layer 412 or a different material.

[0087] The sixth insulating layer 946 has a fourth width W4 in the stripe height direction, extending from the plurality of soft-bias side shields 410, each sensor 920, and the second insulating layer 408 to the surface 401 opposite the MFS. The lower shield 402, the lower conductive line 406, the third insulating layer 640, the first insulating layer 412, and the upper shield 404 each have a first width W1 in the stripe height direction that is greater than the third width W3. The third width W3 and the fourth width W4 are collectively equal to the first width W1.

[0088] As discussed above and as Figure 4C As shown, the lower conductive line 406 between the lower shield 402 and the soft bias side shield 410 has a first thickness T1. The first insulating layer 412 and the upper conductive line 416 between the upper shield 404 and the soft bias side shield 410 collectively have a second thickness T2. The second thickness T2 is substantially equal to the first thickness T1, such that the difference between the second thickness T2 and the first thickness T1 is approximately 50 nm or less. The second thickness T2 being substantially equal to the first thickness T1 facilitates stable read sensor 420, stabilizes the soft bias shield 410, and enhances magnetic read operation while minimizing signal shunting. In addition to the substantially equal first and second thicknesses T1 and T2, the soft bias shield 410 having a third width W3 in the stripe height direction that is less than the first width W1 further stabilizes the soft bias shield 410 through shape anisotropy. The shape and resulting shape anisotropy of the soft bias shield 410 causes the magnetized legs of the soft bias shield 410 to be in a desired direction, such as in a cross-track direction.

[0089] During formation of read head 900, lower shield 402, lower conductive line 406, and read sensor 920 are first deposited. A first photoresist (not shown) is deposited over a portion of read sensor 920 having a second length L2, and the remaining or exposed portion of read sensor 920 is milled away and removed. Second insulating layer 408 and second buffer layer 948 are then deposited. Portions of second buffer layer 948 are removed (e.g., milled) along cross-track direction CT1. Soft bias side shield 410 is then deposited, and the first photoresist is removed.

[0090] A second photoresist (not shown) is deposited over the spacer layer 431 of the free layer 926, the second layer 432 of the free layer 926, the barrier layer 433 of the free layer 926, the cap layer 428, the soft bias shield 410, and a portion of the second insulating layer 408. The remaining or exposed portions of the spacer layer 431 of the free layer 926, the second layer 432 of the free layer 926, the barrier layer 433 of the free layer 926, the cap layer 428, the soft bias shield 410, and the portion of the second insulating layer 408 not covered by the second photoresist are removed, resulting in the portion of the soft bias shield 410 covered by the second photoresist having a third width W3. A sixth insulating layer 946 is then deposited adjacent to the soft bias shield 410, and the second photoresist is removed. The third insulating layer 640, the first insulating layer 412, the upper conductive line 416, and the upper shield 404 are subsequently deposited and formed over the sixth insulating layer 946, the soft bias shield 410, and the read sensors 920. Thus, a self-stabilizing soft bias shield positioned between and outside of a plurality of read sensors in a read head facilitates biasing the magnetic read field of the read sensors during magnetic read operations. The soft bias shield utilizes shape anisotropy for self-stabilization. Thus, during magnetic read operations, the soft bias shield enables a magnetic field in the cross-track direction while minimizing signal shunting, thereby resulting in improved magnetic read operations in the read head.

[0091] In one embodiment, a read head includes: a lower shield having a first width in a stripe height direction; an upper shield; a lower conductive line disposed above the lower shield; one or more upper conductive lines disposed between the lower conductive line and the upper shield in a downward track direction; and a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multilayer structure including an antiferromagnetic (AFM) layer and a free layer. The read head further includes a plurality of soft bias side shields disposed between and outside the plurality of read sensors, each of the plurality of soft bias side shields having a second width in the stripe height direction that is less than the first width.

[0092] Each of the plurality of read sensors has a third width in the stripe height direction that is substantially equal to the second width. Each of the plurality of soft-bias side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance. The free layer includes a first layer and a second layer. The multilayer structure of each of the plurality of read sensors further includes: a buffer layer disposed on the lower conductive line; a barrier layer disposed above the free layer; and a cap layer disposed between the barrier layer and one or more upper conductive lines. The upper shield has a fourth width in the stripe height direction that is substantially equal to the second width. The magnetic storage device includes a read head.

[0093] In another embodiment, a read head includes: a lower shield having a first width in a bar height direction and a first length in a cross-track direction; a lower conductive line disposed above the lower shield; an AFM layer disposed above the lower conductive line, the AFM layer having a second length in the cross-track direction substantially equal to the first length; and a plurality of read sensors disposed above the AFM layer at a medium-facing surface (MFS), each of the plurality of read sensors comprising a multilayer structure including: a portion of the AFM layer and a free layer including a first layer and a second layer. The read head further includes a plurality of soft bias side shields disposed between and outside the plurality of read sensors, each of the plurality of soft bias side shields having a second width in the bar height direction less than the first width; one or more upper conductive lines disposed above the plurality of read sensors; and an upper shield disposed above the one or more upper conductive lines.

[0094] The multilayer structure of each of the plurality of read sensors further includes a buffer layer, wherein the buffer layer is part of a common buffer layer across the plurality of read sensors, and the first layer is part of a common first layer across the plurality of read sensors. The first layer has a third length in the cross-track direction that is substantially equal to the first length. The second layer has a fourth length in the cross-track direction that is less than the third length. The first layer has a third width in the stripe height direction that is substantially equal to the first width, and wherein the AFM layer has a fourth width in the stripe height direction that is substantially equal to the first width. The first layer has a fifth width in the stripe height direction that is substantially equal to the second width, and wherein the AFM layer has a sixth width in the stripe height direction that is substantially equal to the second width. The read head further includes a first insulating layer disposed adjacent to the plurality of soft bias side shields in the stripe height direction, the first insulating layer being recessed from the MFS. The magnetic storage device includes a read head.

[0095] In yet another embodiment, a read head includes: a lower shield having a first width in a stripe height direction; an upper shield; a lower conductive line disposed above the lower shield; one or more upper conductive lines disposed between the lower conductive line and the upper shield in a downward track direction; and a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multilayer structure including a buffer layer, an antiferromagnetic (AFM) layer, and a free layer including a first layer and a second layer. The read head further includes a plurality of soft bias side shields disposed between the plurality of read sensors and outside the plurality of read sensors, each of the plurality of soft bias side shields having a second width in the stripe height direction that is less than the first width. Each of the plurality of soft bias side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance.

[0096] The AFM layer has a third width in the stripe height direction that is substantially equal to the second width. The upper shield has a fourth width in the stripe height direction that is substantially equal to the first width. The AFM layer has a fifth width in the stripe height direction that is substantially equal to the first width. The upper shield has a sixth width in the stripe height direction that is substantially equal to the first width. The first layer has a seventh width in the stripe height direction, and the second layer has an eighth width in the stripe height direction that is less than the seventh width. The first layer has a ninth width in the stripe height direction, and the second layer has a tenth width in the stripe height direction that is substantially equal to the ninth width. The magnetic storage device includes a read head.

[0097] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is to be determined by the claims that follow.

Claims

1. A reader, comprising: a lower shield having a first width in the strip height direction; upper shield; a lower conductor disposed above the lower shield; one or more upper conductors disposed between the lower conductors and the upper shield in a downward trajectory direction; a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multi-layer structure comprising: an antiferromagnetic layer, or AFM layer; and Free Tier; and a plurality of soft-biased side shields positioned between and outside the plurality of read sensors, each of the plurality of soft-biased side shields having a second width in the stripe height direction that is less than the first width, wherein the upper shield has a third width in the stripe height direction that is substantially equal to the second width. 2 . The read head of claim 1 , wherein each of the plurality of read sensors has a fourth width in the bar height direction that is substantially equal to the second width. The read head of claim 1 , wherein the free layer comprises a first layer and a second layer.

4. A magnetic storage device comprising the read head according to claim 1.

5. A reader comprising: a lower shield having a first width in the strip height direction; upper shield; a lower conductor disposed above the lower shield; one or more upper conductors disposed between the lower conductors and the upper shield in a downward trajectory direction; a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multi-layer structure comprising: an antiferromagnetic layer, or AFM layer; and Free Tier; and a plurality of soft-biased side shields positioned between and outside the plurality of read sensors, each of the plurality of soft-biased side shields having a second width in the strip height direction that is less than the first width, wherein each of the plurality of soft-biased side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance.

6. A reader comprising: a lower shield having a first width in the strip height direction; upper shield; a lower conductor disposed above the lower shield; one or more upper conductors disposed between the lower conductors and the upper shield in a downward trajectory direction; a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multi-layer structure comprising: The antiferromagnetic layer is the AFM layer; Free layer; a buffer layer disposed on the lower conductive line; a barrier layer disposed over the free layer; and a cap layer disposed between the barrier layer and the one or more upper conductive lines; and A plurality of soft-biased side shields are positioned between and outside the plurality of read sensors, each of the plurality of soft-biased side shields having a second width in the stripe height direction that is less than the first width.

7. A reader comprising: a lower shield having a first width in the strip height direction and a first length in the cross-track direction; a lower conductor disposed above the lower shield; an antiferromagnetic layer (AFM layer) disposed above the lower conductive line, the AFM layer having a second length in the cross-track direction substantially equal to the first length; a plurality of read sensors disposed above the AFM layer at a medium-facing surface (MFS), each of the plurality of read sensors comprising a multi-layer structure comprising: a portion of the AFM layer; and a free layer comprising a first layer and a second layer; a plurality of soft-biased side shields positioned between and outside the plurality of read sensors, each of the plurality of soft-biased side shields having a second width in the stripe height direction that is less than the first width; one or more upper conductive lines disposed above the plurality of read sensors; and An upper shield is disposed over the one or more upper conductors.

8. A read head according to claim 7, wherein the multi-layer structure of each of the plurality of read sensors further includes a buffer layer, and wherein the buffer layer is part of a common buffer layer across the plurality of read sensors and the first layer is part of a common first layer across the plurality of read sensors. 9 . The read head of claim 7 , wherein the first layer has a third length in the cross-track direction that is substantially equal to the first length, and wherein the second layer has a fourth length in the cross-track direction that is less than the third length.

10. The read head of claim 7, wherein the first layer has a third width in the stripe height direction substantially equal to the first width, and wherein the AFM layer has a fourth width in the stripe height direction substantially equal to the first width. 11 . The read head of claim 7 , wherein the first layer has a fifth width in the stripe height direction substantially equal to the second width, and wherein the AFM layer has a sixth width in the stripe height direction substantially equal to the second width. 12 . The read head of claim 7 , further comprising a first insulating layer disposed adjacent to the plurality of soft-bias side shields in the stripe height direction, the first insulating layer being recessed from the MFS.

13. A magnetic storage device comprising the read head according to claim 7.

14. A reading head comprising: a lower shield having a first width in the strip height direction; upper shield; a lower conductor disposed above the lower shield; one or more upper conductors disposed between the lower conductors and the upper shield in a downward trajectory direction; a plurality of read sensors disposed between the lower conductive line and the one or more upper conductive lines at a surface facing the medium, each of the plurality of read sensors comprising a multi-layer structure comprising: buffer layer; an antiferromagnetic layer, or AFM layer; and a free layer comprising a first layer and a second layer; and a plurality of soft-biased side shields positioned between and outside the plurality of read sensors, each of the plurality of soft-biased side shields having a second width in the strip height direction that is less than the first width, wherein each of the plurality of soft-biased side shields is spaced apart from the lower shield by a first distance and from the upper shield by a second distance, the first distance being substantially equal to the second distance. 15 . The read head of claim 14 , wherein the AFM layer has a third width in the bar height direction that is substantially equal to the second width, and wherein the upper shield has a fourth width in the bar height direction that is substantially equal to the first width. 16 . The read head of claim 14 , wherein the AFM layer has a fifth width in the bar height direction substantially equal to the first width, and wherein the upper shield has a sixth width in the bar height direction substantially equal to the first width. 17 . The read head of claim 14 , wherein the first layer has a seventh width in the stripe height direction and the second layer has an eighth width in the stripe height direction that is smaller than the seventh width. 18 . The read head of claim 14 , wherein the first layer has a ninth width in the stripe height direction and the second layer has a tenth width in the stripe height direction that is substantially equal to the ninth width.

19. A magnetic storage device comprising the read head according to claim 14.

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